九龙江典型流域氮磷流失的模拟研究  

Modeling of Nitrogen and Phosphorus Losses from Agricultural Catchments

作　　者：洪华生[1] 曹文志[1] 张玉珍[1] 陈能汪[1] 曾悦[1] 黄金良[1] 

机构地区：[1]厦门大学海洋环境科学教育部重点实验室环境科学研究中心,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2004年第B08期243-248,共6页Journal of Xiamen University：Natural Science

基　　金：国家教育部博士点专项基金(1999038411);福建省重大科技攻关项目(2002H009)

摘　　要：农业非点源污染是水质下降与环境恶化的主要原因,对地表径流营养盐输出的定量研究有助于掌握流域内非点源污染的来源与贡献,迁移与转化规律.选择福建省九龙江上游两个典型农业流域,在GIS技术支持下,综合采用实地观测、经验参数等方法来确定模型参数,利用2002年5月至8月所有降雨事件全过程实测的水文参数、营养盐氮、磷负荷,对AGNPS(AgriculturalNon PointSourceModel)模型进行调试,使得氮、磷的模拟Nash Sutcliffe效率系数E值都在0.8以上;再利用2002年9月两场降雨全过程数据验证了模型的适用性,验证结果是氮、磷的模拟值相对误差均在7%以下,表明该模型可以较好地估算流域氮、磷输出负荷.应用验证后的模型估算了流域2002年的氮、磷流失,年负荷为总氮27.51kg·hm-2,总磷0.75kg·hm-2;同时发现氮、磷流失主要集中于7～9月暴雨和特大暴雨集中时期,该期间从流域输出的总氮、总磷分别占全年总量的95%、87%.利用AGNPS模型可以有效地估算或预测降雨过程通过径流输送到河流的营养盐,为流域水环境规划管理提供科学依据.Non-point source pollution caused an important environmental and water quality problem,nutrients loss from agricultural catchments is primary concern.The objective of this study was to investigate the applicability of Agricultural Non-Point Source Pollution (AGNPS) Model in Jiulong River catchments and to use the model to estimate total nitrogen and total phosphorus loads at catchment's outlet.The AGNPS model was calibrated using all rainfall events occurred during May to August 2002,in two typical agricultural catchments with different drainage area of 960 hm^2 and 188 hm^2,respectively.Measured data depended on samples collected during each rainfall event.Total nitrogen,total dissolve nitrogen,total phosphorus and total dissolve phosphorus were analyzed for all samples.Some input parameters of the model such as land length and slope extracted from Geographic Information System (GIS) layers.Evaluation of the model was based on measured values against predicted values,Nash-Sutcliffe coefficient was calculated for calibration.High Nash-Sutcliffe coefficient values (>0.80 for total nitrogen and total phosphorus) were obtained.The model was found to be well suited for application in Jiulong River Catchments.The other two rainfall events occurred in September 2002 were used to validate the model.After validating,the AGNPS model was used to estimate nutrient loss from the catchments,with an average total nitrogen and total phosphorus output of 27.51 kg·hm^(-2),0.75 kg·hm^(-2),respectively.Results showed that total nitrogen loss in these catchments is slightly higher than that from some areas in China.Results also showed that the annual loss of nitrogen and phosphorus is mainly caused by several large rainfall events occurred between July and September.95% and 87% of the annual total nitrogen and total phosphorus loss occurred in this period.The AGNPS model would be an effective tool to predict nutrient loading and help develop watershed management program.

关 键 词：AGNPS模型 氮 磷 非点源污染 流域网格划分 农业污染 

分 类 号：X52[环境科学与工程—环境工程] X71